CVE-2010-3096 in FTP Client
Summary
by MITRE
Directory traversal vulnerability in SoftX FTP Client 3.3 and possibly earlier allows remote FTP servers to write arbitrary files via "..\" (dot dot backslash) sequences in a filename.
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Analysis
by VulDB Data Team • 01/07/2018
The vulnerability identified as CVE-2010-3096 represents a critical directory traversal flaw in SoftX FTP Client version 3.3 and potentially earlier releases. This security weakness stems from inadequate input validation within the client's file handling mechanisms, specifically when processing filenames containing "..\" sequences that are commonly used in directory traversal attacks. The flaw allows remote FTP servers to manipulate the client's file system operations by crafting malicious filenames that exploit the client's failure to properly sanitize path references. When the FTP client processes such filenames, it fails to validate the sequence properly, leading to unintended file system modifications. The vulnerability is particularly dangerous because it operates at the client-side application level, where legitimate FTP operations are being performed, making it difficult for users to detect malicious activity. The exploitation requires a remote FTP server to initiate the attack, which means users must trust the FTP servers they connect to, creating a trust-based attack vector that can bypass traditional network security controls.
This directory traversal vulnerability aligns with CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal. The flaw enables an attacker to write arbitrary files to locations outside the intended directory structure, potentially allowing for the creation of malicious files, modification of system files, or even execution of unauthorized code. The "..\" sequence manipulation exploits the client's lack of proper path validation, where the backslash character combined with the dot dot notation can traverse up directory levels. The operational impact extends beyond simple file creation, as the vulnerability could enable attackers to overwrite critical system files, inject malicious code into the client application, or establish persistent backdoors within the user's file system. This type of vulnerability falls under the ATT&CK technique T1059.007 for Command and Scripting Interpreter, as it can enable arbitrary code execution through file manipulation, and T1078.002 for Valid Accounts, since the attack can leverage legitimate user sessions to execute malicious operations. The vulnerability is particularly concerning in enterprise environments where users frequently connect to external FTP servers for file transfers, as it can be exploited to compromise multiple endpoints through a single compromised server.
The mitigation strategies for CVE-2010-3096 require immediate attention and multiple layers of defense to protect against exploitation. Organizations should prioritize updating SoftX FTP Client to the latest available version that addresses this vulnerability, as vendors typically release patches to fix such directory traversal issues. Network segmentation and firewall rules should be implemented to restrict FTP client access to trusted servers only, limiting the attack surface. Additionally, implementing strict input validation and sanitization within the FTP client application can prevent the exploitation of path traversal sequences. Security awareness training for users should emphasize the importance of connecting only to trusted FTP servers and avoiding automatic file downloads from unknown sources. System administrators should monitor file system changes and implement file integrity monitoring solutions to detect unauthorized file modifications. The vulnerability also highlights the importance of principle of least privilege, ensuring that FTP client applications run with minimal required permissions to limit potential damage from successful exploitation. Organizations should also consider implementing network-based intrusion detection systems that can identify suspicious FTP traffic patterns and potentially malicious "..\" sequence usage. Regular vulnerability assessments and penetration testing should include checks for similar path traversal vulnerabilities in other client applications and file transfer protocols to ensure comprehensive security coverage.